The present invention generally relates to surgical instruments, and more particularly, relates to apparatus which provides for improved irrigation and reduced risk of corneal or sclera tissue damage during cataract removal.
Cataracts cause the lens of an eye to become clouded, and a common practice to alleviate this condition is by surgically removing the cataractic lens and replacing it with an artificial intraocular lens.
Early lens removal was effected through manual extraction which required a wound of about 12 mm in length. This large opening can result in corneal or sclera tissue damage.
Phacoemulsification, on the other hand, enables the removal of a cataractic lens through a much smaller incision, for example, between about 2.5 to about 4 mm. In this procedure, a needle is inserted through the incision into a lens capsule and the needle is vibrated to mechanically emulsify the lens. It is often desirable to utilize a second tool in order to manipulate the lens toward and around the phacoemulsification needle in order to more effectively emulsify the lens. Once fragmented or emulsified, the lens material is aspirated through a lumen through the phacoemulsification needle.
Heretofore, while emulsifying the lens and aspirating lens fragments, a simultaneous flow of irrigation fluid into the lens capsule has been provided around the needle through an annulus established by a sleeve concentrically disposed over the needle. This flow of liquid into the eye is necessary to prevent collapse of the interior chamber of the eye during aspiration. In addition, the irrigation fluid cools the needle in order to prevent any thermal damage of the corneal or sclera tissue. While the sleeve surrounding a phacoemulsification needle provides the important function of establishing an annulus for introducing irrigation fluid into the lens capsule it also enlarges the overall diameter of the sleeve needle for which an incision must be made.
In addition, when irrigation fluid is introduced proximate the emulsifying needle tip, the immediate area in front of the needle is roiled. This occurs because of the counter-current flow of fluid being aspirated by the needle itself and the irrigation fluid being introduced over the surface of the needle. Needle vibration causes a cloud of debris which is roiled by the incoming infusion fluid which lessens the physicians visual acuity of the end of the needle which can slow the procedure. This roiling also pushes nuclear fragments away from the needle rendering the procedure less efficient.
The present invention overcomes the drawbacks of a sleeved phacoemulsification needle.
Apparatus in accordance with the present invention includes a first instrument for inserting into a lens capsule and removing a cataract therein, the needle including a lumen therethrough for aspiration of lens tissue and irrigation fluid from said lens capsule through a primary aspiration port defined by an end of said lumen and a second instrument for inserting into the lens capsule and manipulating the cataract as the cataract is being removed, said second instrument having an irrigation port for introducing the irrigation fluid into said lens capsule.
More specifically, the second instrument may include a tip, such as a hook or blade, attached to a shaft for manipulating the cataract and the shaft includes a shaft lumen for delivery the irrigation fluid to the irrigation port. Alternatively, the second instrument may include a conduit attached to the shaft, for delivering the irrigation fluid to the irrigation port. Further, a plurality of irrigation ports may be provided, each in fluid communication with the shaft lumen or conduit.
More specifically, the first instrument may include a sonic or ultrasonic device needle for emulsifying the lens tissue. In this instance, the needle includes a lumen for aspiration of emulsifying lens tissue and aspiration flow from the lens capsule.